Although oral microbiologists initiated the concept that bacterial adherence is a major component of microbial virulence, they have never had the opportunity to convene as a group to discuss problems of mutual interest. We propose to invite 30-35 scientists recognized for their contribution to studies of microbial adherence to a workshop to be held at the University of Pennsylvania in Philadelphia, Pennsylvania, June 5-8, 1984. The workshop will explore the relationships among the biology of adherence and aggregation, the specific molecular interactions between the surfaces of the bacteria and the host substrates, and possible mechanisms for regulation or preventing these interactions. This Workshop is particularly appropriate at this time because advances in the technology of molecular biology have provided new techniques which can be employed to explore the molecular basis for these interactions. The discussion among the variety of disciplines represented at this Workshop should open new areas of inquiry in regard to the specificity of microbial interactions with saliva, salivary pellicle which forms on tooth surfaces, and soft tissues. Questions regarding the importance and mechanisms of intergeneric aggregation as well as the genetic and environmental regulation of the microbial surface molecules involved in these interactions will also be addressed. The clinical implication of these interactions will also be considered both from their contribution to the disease process and to the strategies of plaque prevention based upon an understanding of the molecular interactions. The Workshop should provide a much needed opportunity for investigators in the area to critically evaluate data, provide a fruitful basis for collaborative laboratory and clinical investigations, encourage young investigators to enter field, and above all a fertile source of ideas for new and innovative investigations.